There is no admission that the background art disclosed in this section legally constitutes prior art.
Spinal implants can be anchored to the cancellous bone within vertebrae with the use of pedicle screws. With aging patients, conditions such as osteoporosis can cause deterioration of the cancellous bone within vertebrae resulting in a loosening or backing-out of the pedicle screws. Pedicle screws that loosen or back-out can cause displacement of the spinal implant, thereby resulting in pain in the neck and upper and lower extremities and alignment problems.
Under certain conditions, it can be desirable to remove or change the spinal implant. In these situations, the pedicle screw needs to be removed and potentially reinstalled.
What is needed is a pedicle screw that firmly anchors a spinal implant to the cancellous bone within vertebrae, yet which can be easily removed once installed. The invention provides an improved pedicle screw.